The present invention relates to a module socket and more particularly to an improved socket for use with camera modules of small electronic devices, such as mobile telephones.
Conventionally, module sockets (see, for example, Japanese Patent No. 3620833) have been used for mounting camera modules, each of which is composed of an optical element such as a lens, and an image pickup device such as a CCD (Charge Coupled Device) or CMOS (Complementary Metal Oxide Semiconductor) image sensor, on substrates of small-sized electronic devices such as mobile cellular phones and PDAs (Personal Digital Assistants).
FIG. 7 is a sectional view of a conventional module socket in which the housing of the module socket receives a camera module 302. Two latches 304 are attached to the inner surface of each of two opposed side walls of the socket housing 303. The latches 304 are used to hold the camera module in place and they, as shown, engage corresponding flat latch surfaces 310 that are formed on a stepped portion of the camera module 302. The latches serve to lock the camera module 302 in place in its socket.
Each latch 304 has a free end with latch piece 305 and a latch piece 306 which differ in height from each other. This is done in order to cope with dimensional variations among different types of camera modules 302 of the same type derived from manufacture-related dimensional errors. They cope with the mixed presence of a small-sized module 302a having relatively small outside dimensions and a large-sized module 302b having relatively large outside dimensions. In the case of the small-sized module 302a, the latch piece 306, shown on the right of FIG. 7, whose level is low, is engaged with the latch surface 310, whereas, in the case of the large-sized module 302b, the latch piece 305, whose level is high, is engaged with the latch surface 310.
Meanwhile, terminals 307 are attached to a bottom portion 308 of the socket housing 303 and they project upward from the bottom portion 308 by the effect of their own spring properties. The terminals 307 come into contact with opposing contacts which are formed on the bottom surface of the camera module 302. In the case of the small-sized module 302a, the projection distance of the socket terminals 307 is large, and in the case of the large-sized module 302b, the projection distance of the socket terminals 307 is small.
In this and other conventional camera module sockets, four such latches 304 are used to form a lock mechanism, thereby increasing the number of components and the cost of forming the camera module socket. Also, the use of four such latches requires that all four latches 304 must be handled simultaneously when the camera module 302 is to be detached from the module socket. Manually operating the four latches 304 at the same time is difficult and therefore operability is poor. Furthermore, because of absence of means for restricting the posture of the latches 304, excessive, inward inclination of the latch(es) 304 cannot be prevented. An improper operation of mounting the camera module 302 causes damage to or deformation of the latch(es) 304. If the latches 304 fail to lock the camera module 302 in place with a sufficiently strong force, in some cases, an external impact may cause the camera module 302 to release from the camera module socket.
In order to secure curved portions for the latches 304 so as to lock the camera module 302 with sufficiently effective spring properties, the latches must be a sufficient height. This increase in height creates difficulty in reducing the thickness of the module socket.
The present invention is therefore directed to a camera module socket that overcomes the aforementioned disadvantages.